1. Field of the Invention
The present invention relates to a reflection type display apparatus used for an electronic device such as electronic paper.
2. Description of the Related Art
As a display apparatus that provides good visual recognition and consumes a small amount of power, electronic paper is under active development. As an example of display apparatuses used for electronic paper, an electrochromic display (ECD), which uses a reversible chromatic change caused in a solid or liquid arranged between electrodes by means of voltage application, is known. Also, an electro-deposition type display, which uses deposition/dissolution of metal ions solved out in an electrolyte arranged between electrodes by mean of an electrochemical reaction to display black/white, is known. For example, where electroplating of transparent electrodes is used, it is considered that the display apparatus provides a bright display of highly efficient in the use of light.
Japanese Patent Application Laid-Open No. H11-101994 discloses an example of incorporating color filters in such an electroplating-used display apparatus as mentioned above. The display apparatus disclosed in Japanese Patent Application Laid-Open No. H11-101994 has a silver salt solution arranged between a transparent electrode and a counter electrode, and a porous white background plate with numerous minute holes arranged between the transparent electrode and the counter electrode, and operates to determine the light transmitting state with the transparent electrode, and the reflecting state with the white background plate. Japanese Patent Application Laid-Open No. H11-101994 states that this display apparatus has a micro color filter arranged in each unit cell to display a color image and gradation expression can be realized by controlling the voltage that drives each unit cell, thereby easily providing full color display.
Also, U.S. Pat. No. 5,452,113 discloses a reflection type color display apparatus with an enhanced reflectance for white display. The reflection type display apparatus disclosed in U.S. Pat. No. 5,452,113 has a first dimmer layer in which light scattering and transmitting states can be controlled by an external electric field, and a second dimmer layer in which light scattering and transmitting states can be controlled by an external electric field provided in this order from the light entering side. U.S. Pat. No. 5,452,113 states that for the second dimmer layer, a guest host-type liquid crystal element obtained by mixing and dispersing a dichroic pigment in a liquid crystal may be used.